Electronic control unit having integrated circuit element and standalone test unit for integrated circuit element

Abstract

There is provided a low-cost electronic control unit that is capable of performing its hardware check every start and stop of the electronic control unit. A monitoring and control circuit section that is an integrated circuit element built in the electronic control unit includes a self-test circuit configured with a built-in self-test control block, scan chain circuits and mask circuitry, and performs a self-test using the built-in self-test control block and a partial combination of the scan chain circuits at start of the operation. In the shipment inspection of the integrated circuit element alone, an external test is performed by a checker microprocessor using an entire combination of the scan chain circuits. Thus, the electronic control unit of low-cost configuration is capable of performing a scan test by making use of part of the scan chain circuits designed for the component inspection.

Description

BACKGROUND OF THE INVENTION[0001]1. Technical Field[0002]The present invention relates to an electronic control unit that has an integrated circuit element and is mounted in, for example, a vehicle, and relates to a component test unit that performs in the product shipment stage a rationalized anomaly check associating mutually an anomaly check for the electronic control unit in actual operation with a component anomaly check for the integrated circuit element built in the electronic control unit.[0003]2. Description of the Related Art[0004]In an electronic control unit mounted in, for example, a vehicle that includes an input interface circuit connected to input sensors; an output interface circuit connected to electric loads; and at least one integrated circuit element connected with the input interface circuit and the output interface circuit, the electronic control unit performs during operation a check on connection states of wirings to the input sensors and the electric loads ...

AI Technical Summary

Benefits of technology

[0014]According to an electronic control unit having an integrated circuit element, of the first aspect of the present invention, the integrated circuit element includes a self-test circuit configured with a built-in self-test control block, scan chain circuits, and mask circuitry, and includes the selection command input terminal for switching to select a first combination of the scan chain circuits for, i.e., a partial combination thereof or a second combination of the scan chain circuits, i.e., the entire combination thereof. The built-in self-test control block is enabled during a boot wait period of the electronic control unit or a prolonged power-feed period after stop of operation when the integrated circuit element is mounted on the electronic control unit. A self-test is executed using the first combination of the scan chain circuits excepting at least a scan chain circuit provided in the built-in self-test control block and the mask circuitry for input and output signals. An external test for the second combination of the scan chain circuits including the entire scan chain circuits is executed in the shipment inspection process for the integrated circuit element alone. Therefore, even in the state of integrated circuit element being built in the electronic control unit, the self-test can be performed easily every start or stop of operation of the electronic control unit by making use of part of the scan chain circuits provided for the external test to be executed in the shipment inspection process for the integrated circuit element alone, thus bringing about the advantageous effect of improving reliability of the electronic control unit. Moreover, since some inputs and outputs for the input interface circuit and the output interface circuit are at least disabled during execution of the self-test, an error in the self-test can be prevented from occurring owing to state change in an input signal and an anomalous operation of some electrical loads due to an output of the self-test can also be prevented, thus bringing about the advantageous effect of performing a self-test with high accuracy and high reliability.

[0015]According to a component test unit for an integrated circuit element, of the second aspect of the present invention, the integrated circuit element includes a self-test circuit configured with a built-in self-test control block, scan chain circuits, and mask circuitry, and includes the selection command input terminal for switching to select a first combination of the scan chain circuits, i.e., a partial combination thereof or a second combination of the scan chain circuits, i.e., the entire combination thereof. When the integrated circuit is mounted on the component test unit, an external test is executed for the second combination of the scan chain circuits including the entire scan chain circuit using a second diagnostic pulse-train signal generated by a checker microprocessor, and a self-test for the first combination of the scan chain circuits is executed in the state of the integrated circuit being built in the electronic control unit, using a first diagnostic pulse-train signal generated by the built-in self-test control. Therefore, since in the external test, there is no need for the built-in self-test control block to generate a first diagnostic pulse-train signal and to compare a received first measurement pulse-train signal corresponding to the first diagnostic pulse-train signal with the correct pulse-train information corresponding thereto, an external test can be performed on the built-in self-test control block itself using the scan chain circuits for the built-in self-test control block, thus bringing about the advantageous effect of improving reliability of the integrated circuit element. Moreover, even in the state of integrated circuit element being built in the electronic control unit, the self-test can be performed easily every start or stop of operation of the electronic control unit by making use of part of the scan chain circuits provided for the external test to be executed in the shipment inspection process for the integrated circuit element alone, thus bringing about the advantageous effect of improving reliability of the electronic control unit.

Problems solved by technology

However, no detail checks are made individually on the various combination circuits, with the microprocessor and the monitoring and control circuit section being halted.

In particular, it is difficult to perform quickly the detail checks within a limited permissible time at start of operation; therefore such detail checks have been unachieved.

Therefore, a detail check for various combination circuits cannot be performed by making use of these scan pass circuits (scan chain circuits), with the integrated circuit element assembled into the actual electronic control unit.

Images